#include <fstream>

using namespace std;
ifstream cin("flip.in");
ofstream cout("flip.out");
#define const -1;
int n,m;
int a[101][101];
int spozlinie = 0,sneglinie = 0,spozcol = 0,snegcol = 0;
int s = 0;
int main()
{
    cin >> n >> m;
    for(int i = 1;i<=n;i++)
        for(int j = 1;j<=m;j++)
        cin >> a[i][j];
    for(int i = 1;i<=n;i++)
    {
        for(int j = 1;j<=m;j++)
        {
        spozlinie = a[i][j],sneglinie = a[i][j] * const;
        if(spozlinie < sneglinie)
        for(int j = 1;j<=m;j++)
            a[i][j] = a[i][j] * const;
        }

    }
    for(int j = 1;j<=m;j++)
        for(int i = 1;i<=n;i++)
    {
        spozcol = a[i][j],snegcol = a[i][j] * const;
        if(spozcol < snegcol)
        for(int i = 1;i<=n;i++)
            a[i][j] = a[i][j] * const;
    }
    for(int i = 1;i<=n;i++)
        for(int j = 1;j<=m;j++)
            s += a[i][j];
            cout<<s;
    return 0;
}